Breast cancer is one of the leading causes of cancer-related morbidity and mortality among women worldwide. Despite significant advances in early detection and treatment strategies, clinical outcomes remain highly variable due to tumor heterogeneity and complex tumor–host interactions. In recent years, the tumor microenvironment (TME) has emerged as a central regulator of breast cancer progression, therapeutic response, and patient prognosis. The TME includes immune cells, cancer-associated fibroblasts, endothelial cells, pericytes, adipocytes, signaling molecules, and extracellular matrix components, all of which dynamically interact with tumor cells. These interactions influence tumor proliferation, invasion, angiogenesis, immune evasion, and resistance to therapy. This study, conducted at the Khorezm regional branch of the Republican specialized scientific and practical medical center of oncology and radiology, evaluates the role of the tumor microenvironment in breast cancer treatment outcomes and prognostic stratification. The findings highlight that TME characteristics, particularly immune infiltration, stromal remodeling, and angiogenic activity, are strongly associated with treatment response and survival outcomes.

Breast cancer, tumor microenvironment, cancer immunology, prognosis, tumor-infiltrating lymphocytes, angiogenesis, cancer-associated fibroblasts, immunotherapy, drug resistance

Hanahan D. Hallmarks of cancer: the next generation. Cell. 2011.

Quail DF, Joyce JA. Microenvironmental regulation of tumor progression and metastasis. Nat Med. 2013.

Binnewies M. et al. Understanding the tumor immune microenvironment. Nat Med. 2018.

Fridman WH. et al. The immune contexture in human tumors. Nat Rev Cancer. 2012.

Schmid P. et al. Pembrolizumab therapy in breast cancer. NEJM. 2020.